172 
TliE TROPICAL 
AaPJCULTURIST. 
Sept. 1, 1903. 
THE SUPPOSED NEW SUBSTITUTE FOE 
EUBBER 
MIL PJDLEY OF THE STRAITS BOTANIC 
GARDENS ON THE DISCOVERY. 
Oil the bead of the exciteuient that the allega- 
tions anen'o the Landolphia Thalloni nmsfc have 
caused, says the Straits Times. Jane 27lh, the 
foUowin^'T notes aneni the Lcmdolphias, which 
have been ki.ndiy furnished to us by Mr H N 
Ridley — the Director of the Botanic Gardens and 
the hi^hesi; autiiority upon .such matters in this 
part of ihe world— will prove of the gresitest in- 
terest to all engaged in the cuitivalioa of rubber. 
Mr. Ridley wiites : — 
As in the Straits Times of Thursday you ask for 
inforijaation on Landolphias, perhaps it may in- 
terest your re^i.ders if !. j-^ivg some account of these 
plants. The LandolpJiias are large woody climbers 
occuiriug in the forests of Africa and Madagas- 
car, arid are really hardly distinct from our Will- 
utjhieas, or Getah Grip, so abuud.int in the fore.sts 
of the Malay peninsula. There are about thirty 
kinds of Landolphias known, of which we have 
plants of seven kinds in the Botanic Gardens, 
where they have been cultivated for many years. 
Many grow well and flower constantly, produc- 
ing small white sweet-scented flowers like those 
of our Getah Grips, and one kind has this year for 
the first time produced large, pu'py, orange- 
coloured, sausage- shaped fruits. 
As jungle rubbers supplying a source of revenue 
in heavily forested country, these rubber- vines 
are not to be despised, and the greater part of the 
Congo rubber, of which we have heard so much 
in ootjnection with the Belgian Congo state, is 
derived from the Landolphia. Bat as cultivated 
plants these rubber-vines are very unsatis- 
factory. As your Hollander correspondent states, 
they only produce when cultivated in the open 
slender stems and branches, forming often quite 
a large sized bush but not much thicker than a 
pencil. The bark contains plenty of rubber it 
is true, but to get it out is too expensive to pay 
unless rubber attained a value which it is never 
likely to. I attempted once to extract it by 
cutting the branches into lengths, putting one end 
in the fire so that the heat forced out the latex 
at the other end, and catchina it in a pan, but 
it was such a slow and unsatisfactory business 
that it was clear that it could never he of any 
practical value. The French in Cochin China 
liave manufactured some rubber from the 
Willugbieas there, by treating the bark of the 
vines collected in the woods by natives, with acid 
and extracting the rubber in that way, but with 
the slender twigs and stems of LandolpJiias and 
Willugbieas cultivated in the open,, this would be 
costly, and could hardly be recommended. The 
only likely way to deal with this class of rubber 
plants is to grow them ia partly cleared forests, 
leaviiig enough big trees to act as supports to 
the climbers, and this has beeu done, but the 
plants are not of very rapid growth, and the 
area of land required in proportioji to the return 
which could be reasonably expected is too large 
to tempt planters. To these difficulties one 
must add the fact that these rubber- vines pro- 
duce a quite inferior class of rubber, but it 
is only fair to say that the low price obtained by 
these rubbers is doubtless .due to a large extent 
to Q&reless collection, and adulteration with lower 
grade rubbers practised by the uative rubber 
gatl^erers. I do not know of any Landolphia 
of Africa which produces a better rubber than 
the Willugbcia finna, of our fore.sts. Tliis is 
still plentiful all over the peninbula, and the 
rubber is collected by Sakai.-j an 1 Malays but 
by no means to any large extert, as the prcfits.on 
it are not large. 
The discovery of a new kind of 
Landolphia therefore is not at all likely io 
materially effect the para-ruhber planter, sti'l 
less to rt-volutionize the rubber world unless it 
possesses much higher qualities than those of the 
other kinds. With a very large area of Tropical 
Africa unexplored botanically, one may very 
reasonably expect the discovery of half a dozen 
new kinds within the next few , ear?. 
In justice to ihe, Landolphias one must admit 
that they certainly saved the si - uation for the pa.'it 
20 or 30 year.s. Rubber which could hardly have 
been said to have been cultivated at all" then, 
began to get very scarce, owing to the destruction 
of so many of the more acces.-sible of the S nitli' 
American trees. When Landol/ Mas were dis- 
covered to be very abundant over large areas in 
Africa, the forests containing them were exploited 
and the rubber brought into the markets in large 
quantities, to such an extent that the market gob 
over-stocked, and at the same time the more acces- 
sible forests were depleted. Indeed alre .dy some 
large areas formerly producing rubber inconsider- 
able quantity are now worked out. 
From the planter's point of view it is distinctly 
to hia interest that these jungle rubbers should be 
discovered and worked out as quickly as po.ssible, 
in order that he may get an open field for his 
product. L-mdolphia Thalloni, the root rubber 
to which you refer, is a little shrub about six 
inches tall. As a curiosity it is well worth intro- 
ducing here, and I have no doubt that we shall 
soon have it. As a plant of practical utility it is 
hardly up to our requirements, as the rubber is 
diificult to extract clean, ami fetches a very 
low price. It was discovered in li^Q. — Straits 
Times, June 27. 
^ 
CITRONELLA OIL- 
The investigation in regard to the iiidentity of a 
new adulterant of citronella oil and the failure of 
Schimmel's test to detect it is brought to a fitting 
conclusion by Messrs Parry and Bennett. We 
understand that observations by Messrs Schim-- 
mel & Co.'s chemises confirm generally the' 
conclusion to which the English workers have 
come, except that the adulterant may be a frac- 
tional distillate of Russian pretroleum — a fact 
which Messrs Parry and Bennett have i?idicated to 
be not improbable, as there is considerable simila- 
rity in properties between certain fractions of that 
petroleum and those of resin spirit. This, however, 
is a secondary matter compared with the exposure 
of the adulteration which the English workers have 
ma;?e, and which has created considerable interest 
in Ceylon. We would fane hope that the Ceylon 
Government gave assistance in the matter, but are 
not sanguine that anything Government may do 
will stop the propensity of some native distillers and 
dealers to sophisticate their products. A constant 
cheek must be kept on essential oils which come 
from the East, and so far as citronella oil is con- 
cerned the analytical factors given by Messrs Parry 
and Bennett will suffice to show vvlien the oil is or 
is not pure — Chemist and Druggist, Jiiue 20. 
